1. Field of Invention
The present invention relates to a method and apparatus for transmitting and delivering a confidential message or document in a manner which prevents access to the contents without producing visible evidence of tampering.
2. Brief Description of the Prior Art
Over the centuries, written communication has become essential to conducting both business and personal affairs.
As the subject matter of these communications became increasingly private in nature, there arose a problem regarding their confidential transmission. Short of folding, sealing or encapsulating the message in a sealed tube for delivery, the integrity of those involved in the transmission and delivery of the message was relied upon for preserving confidentiality. A natural solution to this problem was provided in large part by the envelope. To date, the envelope, in its numerous embodiments, is the method of choice to ensure confidentiality through the delivery process.
With the advent of telegraphy and telegraphic messages, such as telegrams, an additional technique of message transmission was established. However, the need for preserving confidentiality rendered this communication technique less than desirable. In response to this problem, U.S. Pat. No. 2,396,833 discloses a telegraph receiving blank adapted to conceal the body of the recorded message, thereby preventing unauthorized access during handling and delivery. In the decades following the developing of the above-mentioned telegraph receiving blank, a variety of facsimile machines have been developed which incorporate printers utilizing thermally sensitive paper. Machines of this type, however, have been generally adapted to receive and print messages of varying length and thereafter automatically cut the thermally sensitive paper at the end of the message. Consequently, the continuous strip of recording blanks proposed in U.S. Pat. No. 3,296,833, cannot be utilized with thermal printing facsimile machines since the severing operation, occurring at arbitrary points along the continuous strip, frequently severs the sealed blank along the message recording area.
With similar security concerns in mind, U.S. Pat. No. 3,261,911 broadly describes a prior art transmission system for use in modernizing the postal delivery system. Generally, the proposed facsimile transmission system contemplated the use of a central transmitting station at which sealed mail envelopes were mechanically opened with automated equipment, then scanned to produce facsimile messages which would then be transmitted to a remotely located central receiver station. At the central receiver station, the received facsimile message would then be automatically reproduced and mechanically enclosed in an enclosure which was addressed and subsequently sealed. Thereafter, the enclosed addressed envelope could be picked up by or physically delivered to the addressee in the normal course of mail delivery. This proposed system was generally rejected by the postal system for having a number of shortcomings and drawbacks. In particular, this proposed system was deemed inherently prone to mechanical breakdown and the likelihood of concomitant loss of facsimile messages, and thus was essentially abandoned.
As an alternative to the above described system, U.S. Pat. No. 3,261,911 proposes a system for transmitting imprinted intelligence, in which an intelligence bearing message to be transmitted is placed in a sealed enclosure opaque to visible light. The opaque sealed enclosure is then scanned at the transmitting location using x-radiation to produce an intelligence bearing signal. The intelligence bearing signal is then transmitted over a communication medium to a remote location. At the remote location, a converter converts the intelligence bearing signal into a voltage, which is used to reproduce the original intelligence upon voltage sensitive paper sealed within an enclosure also opaque to visible light. While such a system does provide a way of ensuring confidentiality of facsimile messages, it nevertheless requires necessarily complex equipment and technical measures.
As with previous technology involving written communication, present day facsimile machines have not been without concern regarding confidentiality.
In particular, prior art techniques have been proposed involving the use of facsimile machines having "electronic mailbox" capabilities, to secure facsimile transmissions. In such systems, confidential messages destined for a particular individual are not printed upon receipt, rather they are stored in an assigned electronic mailbox or memory location within the facsimile machine. When the individual desires to read his or her mail, an assigned access or security code is inserted, whereupon the stored messages are printed. While such techniques can provide a certain degree of confidentiality, they require that the recipient or an authorized agent access the stored messages from the facsimile machine.
Thus, while several approaches have been proposed for preventing casual reading of confidential messages, such techniques have suffered from shortcomings and drawbacks of the type described above.
As a result, there remains a need for improved facsimile apparatus capable of delivering hard-copy facsimiles in a manner which prevents casual reading of the contents.
Accordingly, it is a primary object of the present invention to provide a method and apparatus for delivering secured hard-copies of confidential messages in a manner which overcomes the shortcomings and drawbacks of prior art methodologies and apparatus.
Another object of the present invention is to provide a method and apparatus for delivering facsimile documents to remote locations at the speed of facsimile signals and over public telecommunication systems, with the information content of the facsimile document being maintained confidential as done in normal postal and courier service operations.
It is a further object of the present invention to provide such apparatus in the form of a single facsimile transmitting and receiving unit which uses encoding and decoding technology to selectively encode facsimile data signals with command codes indicative of predefined operations to be enabled or disabled at a selected receiving station.
It is a further object of the present invention to provide such apparatus in the form of a single facsimile transmitting and receiving unit which uses symbol recognition technology to determine whether the facsimile message is to be reproduced as a secured, hard-copy document.
It is a further object of the present invention to provide such apparatus in the form of a single facsimile transmitting and receiving unit which uses signal decoding technology to determine whether the facsimile message is to be reproduced as a secured, hard-copy document.
It is a further object of the present invention to provide such a facsimile transmitting and receiving unit, in which confidential messages of any length, can be electronically transmitted and subsequently reproduced as a secured, hard-copy facsimile.
Still a further object of the present invention is to provide such a facsimile transmitting and receiving unit, in which the hard-copy facsimile document can be concealed so that a non-confidential portion of the facsimile message is rendered visible, while a confidential message portion is concealed in a manner that would provide visual evidence of tampering.
It is a further object of the present invention to provide such a facsimile transmitting and receiving unit having a charge metering control mechanism in which charge data stored in the facsimile unit enables the controlled operation of the transmitting component of the facsimile unit so long as metered accumulation of computed charge does not exceed a preallocated charge remotely delivered to the facsimile unit.
An even further object of the present invention is to provide such a facsimile transmitting and receiving unit having a charge metering control mechanism, in which preallocated charge can be purchased in advance of unit utilization by, for example, placing a charge order by telephone to a designated charge purchase station. Such a facsimile system would be most suitable for rental applications providing discounted facsimile transmission charge rates.
An even further object of the present invention is to provide such a facsimile transmitting and receiving unit, in which selected information content of reproduced facsimile documents can be rendered concealed using one of a variety of facsimile information concealing technologies.
Another object of the present invention is to provide an accessory device for use in connection with a conventional facsimile machine, and which is capable of intelligently concealing selected information content of facsimile documents produced by the conventional facsimile machine.
Another object of the present invention is to provide such a facsimile accessory device, in which symbol recognition technology is employed to read symbols indicative of machine commands instructing the concealment of the confidential information bearing portions of facsimile documents produced from conventional facsimile machines.
These and other objects of the present invention will become apparent hereinafter and in the claims.